ANALYTICAL METHODS FOR GROWING MEDIA – CHALLENGES AND PERSPECTIVES
Production methods in modern horticulture demand an equivalent choice of suitable substrates. Starting with rather simple systems, today growing media are complex mixtures with a still growing number of possible constituents. Analytical methods to characterize growing media in terms of plant response were initially derived from soil analysis. Nowadays, it is a separate field with a high degree of specialization, as a sufficient characterization of the matrix is a basic requirement for the successful use of growing media. In the beginning, substrate analysis has focussed on several key parameters like bulk density, pore space, pH, salt content or soluble nutrients. The development of new matrices increases the number of essential methodologies like detailed physical characterization or biological properties. According to local demands, individual approaches with varying focus have been developed for equal or similar properties. Moreover, certain groups have also differing demands to be met: substrate producers are in need of tools for quality control, trade and inspection require well standardized and comparable methods and for the growers, the surveillance of the plant production is of main importance. Therefore, depending on the purpose or simply on the national methods for one and the same feature may differ to quite a large extent. To assure comparability, work has to be done not only to develop and verify new methods but also to define general standards especially for the key parameters. Furthermore, these standard methods have to be calibrated on the basis of the corresponding old approaches to guarantee continuity of control or recommendation systems. Activities of the Centre Européen de Normalisation (CEN) or the EU-funded project "HORIZONTAL" can be seen as a second starting point. Although all EU countries have accepted and implemented some of the so far established EN-standards, other nationally or otherwise established methods are still in use as there are still disadvantages for routine analysis and consulting work. ISHS can serve as a basis to improve this situation.
Baumgarten, A. (2008). ANALYTICAL METHODS FOR GROWING MEDIA – CHALLENGES AND PERSPECTIVES. Acta Hortic. 779, 97-104
growing media, analytical methods